"We are pleased to welcome Ms. Lewis-Raymond and Ms. Thornton as new directors. These proven leaders bring decades of experience to the company and strengthen our culture and commitment to safety, growth and sustainability," John P. Hester, Southwest Gas Holding's President and Chief Executive Officer, said. "They join Southwest Gas at an exciting time as we continue to aggressively grow our natural gas operations and utility infrastructure services business segments. To attract such high caliber industry executives, who we expect to bring new and diverse perspectives to our Board, is an honor."

"The addition of these directors complements our Board's skills and experiences, and we are confident they will provide valuable perspectives as we continue to execute our strategy, drive profitability and enhance value for all Southwest Gas Holdings shareholders. We look forward to their contributions and are excited that they have chosen to be a part of Southwest Gas Holdings."

As directors, Ms. Lewis-Raymond will serve on the Audit and Nominating and Corporate Governance Committees and Ms. Thornton will serve on the Audit and Compensation Committees of the Company's Board.

Ms. Lewis-Raymond has served the natural gas industry for nearly three decades. Currently, Ms. Lewis-Raymond is a partner with Parker Poe Adams and Bernstein in Charlotte, North Carolina, where she co-leads the Governance, Risk and Compliance Practice Group and is a member of the firm's Energy Practice Group. She retired from Piedmont Natural Gas Company Inc. ("Piedmont") in 2016, following the acquisition of Piedmont by Duke Energy Corporation, where she was a senior officer and member of the Executive Management Team, leading top line growth and measurable strategic and sustainability directives to build long-term value for shareholders. During her ten-year tenure with the company, she rose from General Counsel and Corporate Secretary to Senior Vice President, Chief Legal, Compliance and External Relations Officer. During her time at Piedmont, she implemented several corporate governance initiatives relating to enterprise risk management, cybersecurity readiness, crisis management planning and board succession planning.

Earlier in her career, she was with the American Gas Association, as Vice President of Regulatory Affairs. Ms. Lewis-Raymond is the Co-chair for the Teach For America Charlotte-Piedmont Triad Advisory Board and serves on the National Advisory Council for Teach For America, the Board of Directors for MeckEd, the Steering Committee for The Keystone Energy Board, and is a member of Women Executives. She is a graduate of the University of Maryland and an Order of the Coif graduate of the University of Maryland School of Law.

About Leslie T. Thornton

Ms. Thornton began her career in the utility industry as a senior executive in 2011 for WGL Holdings, Inc. ("WGL") and Washington Gas Light Company, a wholly-owned subsidiary of WGL and served in elevated roles until becoming the Senior Vice President, General Counsel and Corporate Secretary in 2014. She assumed the position of Senior Vice President, Merger Transition Counsel following the 2018 acquisition of WGL by AltaGas and will end her employment with WGL on November 30, 2018. During her WGL tenure, Ms. Thornton earned her Master of Laws degree in National Security Law with a cybersecurity focus from Georgetown University Law Center and provided legal counsel on a broad range of issues including critical infrastructure cybersecurity and data protection.

Before joining WGL, Ms. Thornton was a partner at two national law firms focusing on internal corporate, federal and state attorney general investigations, appellate litigation, and homeland security issues. In the Clinton administration, she served in the U.S. Department of Education and was Chief of Staff to the Secretary of Education. Since 2005, she has been a member of the Board of Directors for Career Education Corporation, where she serves on the Audit Committee and chairs the Compliance and Risk Committee. Previously, she served as Lead Independent Director of Career Education Corporation. Ms. Thornton is a Board Leadership Fellow for the National Association of Corporate Directors. Ms. Thornton serves on the Metropolitan Board of Directors for the Boys and Girls Clubs of Greater Washington, the Board of Trustees for the University of the District of Columbia David A. Clarke School of Law, and the Board of Governors for the District of Columbia Bar. She is a graduate of the University of Pennsylvania and Georgetown University Law Center.

About Southwest Gas Holdings

Southwest Gas Holdings has two business segments:

Southwest Gas Corporation provides safe and reliable natural gas service to over 2 million customers in Arizona, Nevada and California.